How do you change a thermostat on a 1997 Oldsmobile silhouette?

The thermostat is located on the left side of the engine block.
Follow the top radiator hose back and it will lead you to the
housing. You'll need to remove the air filer and hoses that are in
your way and I recommend having a swivel adaptor handy to reach the
rear bolt on the housing. It is a very tight fit to get to and make
sure you give yourself a couple hours to finish it up.